PLATE XI 



Fig. I. — Diplotene in Chorthippus ^, showing precocity of P chromo- 

 some which is attached to X. It has a single interstitial chiasma. 

 (D., 1936 d.) 



Figs. 2-4. — First metaphase in Hemerohius hunmlinns (Neuroptera), 

 showing non-pairing or " distance conjugation " oi X and Y. 



Fig. 2. Side view. Fig. 3. Polar view. Fig. 4. Two auto- 

 somes also unpaired. (Klingstedt, unpublished.) 



Fig. 5. — Non-pairing of X and Y in the mammal Putorius furo 

 (ferret), showing similar arrangement on opposite sides of the plate. 

 (Koller, unpublished.) 



Fig. 6. — First metaphase in man ; X and 1' paired terminally and 

 lying off the plate. (Koller, unpublished.) 



Figs. 7 and 8. — First metaphase in the rat, showing pairing of X 

 and Y, (Fig. 7) terminally to give reductional first division separation 

 and (Fig. 8) interstitially to give a S3^mmetrical bivalent having equa- 

 tional first division separation. (Koller and D., 1934.) X 2400. 



